finding the PID of a process running as an anonymous pipe

[Richard]

I need to find the PID of a process running as an anonymous pipe, that is I
have this code

$fh = new FileHandle;
open($fh, "tail -f $filename |") or die ..........

I want to get the PID of the tail -f process when runing under linux, I
could do it by looking at the output of ps -fwu $userid | grep "tail -f
$filename", but that seems like over kill

Thanks.
Richard.

 

[Anno Siegel]

I need to find the PID of a process running as an anonymous pipe, that is I
have this code

$fh = new FileHandle;
open($fh, "tail -f $filename |") or die ..........

I want to get the PID of the tail -f process when runing under linux, I
could do it by looking at the output of ps -fwu $userid | grep "tail -f
$filename", but that seems like over kill

"perldoc -f open" will answer that. Also see "perldoc -q tail".

Anno

 

[Brian McCauley]

I need to find the PID of a process running as an anonymous pipe,

I know you've no RTDMed at Anno's suggestion so I won't adderess that.

$fh = new FileHandle;

In recent Perl the above is redundant - open() autovivifies.

open($fh, "tail -f $filename |") or die ..........

In recent perl rather than combining the mode and all the exec()
arguments into a string and having perl (or even /bin/sh) pull them
appart again, you can acually give them as a list. This is far cleaner.

open($fh, '-|', 'tail', '-f', $filename) or die ..........